The primary goal of the Plasma Dynamics Modeling Laboratory (PDML), directed by Professor Ken Hara, is to develop numerical methods and theoretical models in order to understand the physical phenomena in various plasma discharge and flows. Current applications include electric propulsion (EP) and fundamental plasma physics phenomena including plasma-material interactions, plasma-wave interactions, and plasma-beam interactions.
In EP systems, ions are accelerated with the electromagnetic fields to obtain thrust. Much faster exhaust velocity of the ions results in better fuel efficiency (i.e. specific impulse) in comparison to conventional chemical rockets. Hence, EP devices have been and will be increasingly employed for communication satellites, deep space missions, and interplanetary spacecraft. From the perspective of plasma physics, EP plasmas operate around 10 - 50 eV (electron-volts). This is a unique regime where dynamics of both low and high temperature plasmas could play an important role, which makes the physics very interesting and complex. Go to About page.
Plasma is an ionized gas and is often referred to as the 4th state of matter. The characteristics vary depending on the plasma parameters such as gas pressure, plasma density, and electron temperature. In gas kinetics, the velocity distribution functions (VDFs) of the gas species play an important role in the overall gas dynamics and chemical reactions. When the flow is collisional, the VDFs relax to Maxwellian distribution, for which fluid description (conservation laws) is valid. On the other hand, when the flow is rarefied or collisionless, the VDFs can be any non-Maxwellian distribution and kinetic approach must be used. The gas dynamics is further coupled with the electromagnetic forces, which further make the system more nonlinear and complex.
PDML develops fluid methods (computational fluid dynamics, magnetohydrodynamics, etc.), kinetic methods (particle-in-cell, direct kinetic simulation, etc.) as well as hybrid models, in which multiple different methods are used simultaneously in one single simulation. In order to model real-world systems using high-fidelity models, high performance computation (parallel computing) using supercomputers is also pursued. In addition to the numerical simulation techniques, we focus on developing theoretical models and framework that can help us explain the complex phenomena. Go to Research page.
As scientific challenges become increasingly complex and multidisciplinary, PDML places great emphasis on collaborations with other experts in the field nationally and internationally. Our collaborators include colleagues at Stanford University, other universities, national laboratories, governmental research laboratories, and industry. Go to Links page.
We are looking forward to working with students, undergraduate or graduate, and researchers (postdocs, visitors) who are excited to work on multidisciplinary problems from both physics and engineering perspectives. Please contact us.